Multiple-speed planetary-gear transmission mechanism



Feb. 16 1926. 1,573,098

F. SMALL ET AL MULTIPLE SPEED PLANETARY GEAR TRANSMISSION MECHANISMOriginal Filed May 29, 1924 Patented 16, 1926.

UNITED STATES PATENT OFFICE.

run I. SHALL I. NIGEL, 0m, GALII'OBNIL HULTIPLE-BIIED PLANETA BY-GEABMECHANISM.

Original application filed Kay 28, 1924, Serial No. 718,559. Divided andthleappllcatlon Med December 16, 1924. Serial No. 758,210.

' CARL E. NAGEL, citizens of the United States,

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residing the said SMALL at the city of Oakland, in the county of Alamedaand State of California, and the said NAGEL also at Oakland, in thecounty of Alameda, Cahfornia,'have invented certain new and usefulImprovements in Multiple-Speed Planetary-Gear Transmission Mechanisms,of which the following is a specification.

This is a division of our pending application Serial No. 716,559, filedMay 29, 1924-, and relates to power transmitting mechanisms of theplanetary or epicyclic lhe general object of the invention hereinclaimed is, as set forth in said pending parent application, to providea transmission mechanism of the described type in whlch a plurality ofdifierent speed ratios may be obtained with a minimum number of parts.More specifically, our present objects are to rovidea planetarytransmission mechanism from which three difi'e'rent forward speed ratiosand one reverse may be obtained by the use of only three concentricgears connected by one or more planet members, each consisting of buttwo pinions; and to provide such a mechanism in a form suitable for usein power driven vehicles of the usual type in which the engine ispositioned longitudinally of the vehicle, and its power transmitted tothe axle by a longitudinally disposed shaft. I

Our herein described mechanism is therefore especially adapted forautomobiles, motor trucks, tractors, and such types of railway motorcars and locomotives as have a longitudinally disposed driving shaft,for the reason that the driving and driven shafts in said mechanism areaxially aligned. It.

is well suited, moreover, for use in heavy vehicles, such as trucks,busses, rail cars and locomotives, in which it is highly desirable tomaintain the engine in driving connection with the wheels at all times,even when shifting from one speed ratio to another. Furthermore, it maybe advantageously used in such heavy vehicles, in which the reducedspeed ratios mustbe employed to a considerable extent, because onaccount of the comparatively small number of gears and other movingparts, the friction losses on such reduced speed ratios are relativelylow.

Other ob'ects and advantages of the invention will become apparent fromthe following specification. It is to be understood, however, that theform and construction of the mechanism may be varied from that shown anddescribed, within the limits of the claims hereto appended, withoutdeparting from the essential principles of the invention as set forth insaid claims. It is also to be understood that our mechanism is notlimited to use in vehicles, but may be employed in any situation inwhich a variable speed power transmitting mechanism is needed. I

With this in view, our invention will now be fully described withreference to the accompanying drawing, in which the figure is alongitudinal partial section of a transmission mechanism embodying apreferred form of the said invention.

in the drawing, the reference numeral 1 designates a fixed frame. 2 isthe shaft of an engine, not shown, and 3 is the usual fly wheel securedto the end thereof. at is a shaft for transmitting power to the drivingwheels, not shown, ofthe vehicle, said shaft constituting the drivenmember of the mechanism. The driven shaft 4 has a hearing at 5 in theframe 1, and its forward end is preferably journaled at 6 in the flywheel 3.

Secured to the engine fly wheel 3, and journaled upon the forward end ofthe shaft 4: is a sleeve 7 whose rear end is secured to or formedintegrally with a plate 8, and said plate is secured to a drum. orcylindrical housing 9. Said housing has secured to it an opposite endplate 10 and a central plate 11, and encloses two friction clutchesrespectively designated by the letters A and B.

The clutches A and B may be constructed in any suitable manner, but forpurposes of illustration we have shown them as of the multiple plate ordisk type. The clutch A comprises two sets of alternately disposed disks12 and 13 respectively, the former being freely keye'd or splined, asindicated at 14, to the housing 9, and the latter similarly keyed orsplined, as indicated at 15, to a sleeve 16 journaled upon the shaft 4:.As a means for operating said clutch A, we have shown slidable pins 17extending through the housing end plate 8, and hearing against theendmost of the friction disks 12. Bell cranks 18, provided withadjusting screws 19, act upon said pins 17, and are 1 connected bytoggle links-20 with a collar .21 slidably mounted upon the drivingsleeve 7, and a thrust .rin 22 is rotatably carried in said collar 21 anmay be connected in the.

keyed .or 'splined, at 25-and 26 respectively,

to the housing 9 and to a sleeve 27 journaled 'about the sleeve'16, andsaid disks are pressed" together, and against the central housing late11, by pins 28 slidably mounted in the iiousing. end plate 10. .Bellcranks 29 are provided with adjusting screws 30 to bear against saidpins 28, and are connected by toggle links 31 with a collar 32 shdablymounted upon the hub 33 of the housing plate 10, and said collar isprovided with a thrust ring 34 which may be connected with any suitableoperating mechanism not shown.

The sleeve 16, which may be connected withthe driving member 2 and thesleeve 7 bythe clutch A, carries a sun pinion 35. The sleeve 27, whichmay be connected with said driving member by the clutch B, carries adrum 36, to which is secured, as by screws 37, an end'member 38 having ajournal 39 about the shaft 4. An internal gear 40 is formed within.said' end member 38, and therefore rotates with and is virtuallX a partof-the drum Y36 and the sleeve 27.

second sun pinion 41 is carried by a sleeve 42 journaled between theshaft 4 and the end member 38, and is positioned in transverse ali mentwith said internal gear 40 A secon for contracting said bands to causethem by a prefera to frictionally grip their respective drums and holdthe same stationary.

Between the longitudinally spaced sun pinions 35 and 41 is a spider 47secured upon'the driven shaft 4 as by means of a key 48. Said spidercarries a plurality of rotatable,planet pinion members, one of which isshown journaled in said spider at 49, and which comprises a planetpinion 50 adapted to mesh with the sun pinion 35 anda second planetpinion 51 adapted to mesh with both the internal gear 40 and the sunpinion 41. Said planet pinions are connected together ly integralspindle 52. Thus and their spindle 52.

the. mechanism above drum 43 is secured to the sleeve 142 of said secondsun pinion 41, as by means the sun pinions 35 and 41 and the internal.gear' 40, whichare ill concentric, are connected togetherthrough theplanet pinion me r comprising the pinions 50 and 51 The bwperation ofdescri provides three different speed ratios in a forward direction, andone're- I verse. The lowest. forward speed is ob-. ta ned by connectingthe sun pinion 35 with the driving A, and-ho dingthe internal. gear-4Ostation-' member 2 by means of the clutch ary by meansof its-brake D.This causes the planet members to travel around the stationary internal.car 40 under the imelling action of sai y rotating the spider 47 and theshaft 4 in the same direction as said sun pinion 35 but.at a slowerspeed. Assuming, for example, that the pitch diameter ratio between thevarious gears is one for the planet inion 51, two for the planet pinion50, t ree for the sun pinion 35, four for the sun pin- 'ion 41, and sixfor the internal gear 40, then the speed ratio between the drivin anddriven members will be five to one. T 'c Sun pinion 41 'revolves idlyunder such conditions. w

The next, or intermediate forward speed is obtained by connectintheinternal gear 40 with the driving mem er 2 by meansof the clutch B,and'holding the sun pinion 41 stationary bymeans of the/brake C. The sunpinion 35 revolves idly. Assuming the same pitch diameters as above, thespeed ratio under these conditions will be 1.66 to 1.

The highest speed, or direct one to one drive is o tained by connectingboth the sun pinion 35 and the internal gear 40 with the driving member2, by engaging both clutches A and B. The entire mechanism then revolvesas a unit. Conversely, when both said clutches are disengaged, thedriving member 2 revolves idly, and no power is transmitted.

The reverse speed is obtained by connecting the sun pinion 35 with thedrivin member 2 by means of the clutch A, an holding the sun pinion 41stationary by means of itsbrake C. The internal gear 40 revolves idly.The speed ratio under such sunpinion 35, there conditions will be 1.66to 1, with the driven Y shaft 4 rotating in the reverse direction fromthe driving member 2. In any of the above combinations, thedriven shaft4 may be braked by applying both brakes C and D at the same time.

It should be noted that, by the mechanism above described, we are ableto provide three different forward speed ratios and one reverse with butthree concentric gears and one set of planet members, each such memberconsisting of but two connected pinions. This result is renderedpossible by the arrangement of the clutches and brakes, and

by the provision of two concentric gears (40. and 41) meshing with thesame planet pinion (51).

It should also be noted that the driving and driven members are axiallyaligned and are at opposite ends of the mechanism, thus renderin itparticularly adaptable to vehiclelsl in w ich the driving shaft islongitudina mechanism is fully enclosed, the clutches by the housing 9and the gears by the drum 36. Moreover, by positioning both clutches atone end of the mechanism, they may be madeof ample size to carry thenecessary loads.

We claim 1. In a device for the described purpose, a driven shaft; adriving member journaled thereupon; a rotatable drum journaled upon saidshaft; a plurality of coaxial gears housed within said drum: meansmounted aboutsaid shaft and positioned exteriorly to said drum at oneend thereof for selectively connecting two of said said driving .member;means for releasabl holding one of said gears stationary; an a planetpinion member carried by the shaft and adapted to mesh with and connectsaid coaxial gears.

80 2. In a device for the described purpose a connecting two of saiddisposed, and further that the entire gears with driven shaft, a drivingmember journaled thereupon; a rotatable drum journaled upon said shaft;a plurality of'co-axial gears housed within said drum, one of said gearsbeing secured thereto; a pair of-clutches positioned about said shaftexteriorly to said drum at one end thereof for selectively gears withsaid driving member; means for releasably holding one of said gearsstationary; and a planet pinion member carried by the shaft and adaptedto mesh with and connect said 00- axial gears, t

8. In a device for the described purpose, a driving member; a drivenshaft; a plurality of co-axial gears journaled upon said shaft; ahousing secured to said driving member and journaled about said shaftand longitudinally spaced from said gears; clutches within said housingfor connecting it selectively with two of said gears; means forreleasably holding one of said gears stationary; and a planet pinionmember carried by the shaft and adapted to mesh with and connect saidco-axial gears.

In testimony whereof we have signed our names to this specification.

FRED F. SMALL. CARL E. NAGEL.

